Turbocharger bearing retention and lubrication system

Abstract

A turbocharger includes a rotating shaft which is supported within the turbocharger center housing by rotational bearing elements. The bearing cartridge is located axially within the housing 14 by a pin which extends through orifices drilled in the center housing and in the bearing outer ring. The pin is relatively smooth, so that excursions of the bearing cartridge assembly with the shaft is permitted when the shaft is accelerated through critical rotational speeds. These excursions are damped by lubricating fluid communicated into grooves circumscribing the bearing outer ring through lubrication passages extending through the pin. The lubricating fluid in the grooves communicates into the intersticial space defined between the outer ring of the bearing cartridge assembly and the center housing to thereby dampen the excursions of the bearing cartridge assembly.

What is claimed is: 
     
       1. Exhaust gas driven turbocharger comprising a housing, a shaft within said housing having a longitudinal axis of rotation and a pair of ends, a compressor wheel mounted within said housing on one end of the shaft for rotation therewith, a turbine wheel mounted within said housing on the other end of the shaft for rotation therewith, means for communicating air to said compressor wheel, means for communicating exhaust gas to the turbine wheel to cause the latter to rotate the shaft and the compressor wheel mounted thereon to compress the air communicated to the compressor wheel, and bearing means mounting said shaft for rotation relative to the housing, said bearing means including a bearing outer ring, a bearing inner ring, and ball bearing elements supporting the bearing outer ring on the bearing inner ring, a bearing locating aperture in said bearing outer ring, and an elongated bearing location pin having a longitudinal axis of symmetry extending transversely to said longitudinal axis of the shaft, said pin being carried by said housing and engaging said aperture for locating said bearing assembly in a predetermined position with respect to the housing while permitting movement of said shaft and the bearing assembly along the axis of said pine to accommodate excursions of said shaft when the rotational speed of the shaft passes through critical speed ranges. 
     
     
       2. Exhaust gas driven turbocharger as claimed in claim 1, wherein said housing includes a circumferentially extending wall circumscribing said shaft, said pin extending through said circumferentially extending wall. 
     
     
       3. Exhaust gas driven turbocharger as claimed in claim 2, wherein lubrication passage means extends through said pin to communicate lubricating fluid from outside of said housing to said bearing elements. 
     
     
       4. Exhaust gas driven turbocharger as claimed in claim 3, wherein one end of the pin extends through said wall, said lubrication passage means including a fitting on said one end of the pin for engagement with a lubrication supply line for communicating said lubricating fluid into said passage. 
     
     
       5. Exhaust gas driven turbocharger as claimed in claim 3, wherein said lubrication passage means includes a first portion within said pin, a chamber defined between said pin and said housing, and a second portion extending through the wall of the housing to communicate the chamber with the bearing elements. 
     
     
       6. Exhaust gas driven turbocharger as claimed in claim 5, wherein said lubrication passage means includes a flow restricting orifice between said first portion and said chamber. 
     
     
       7. Exhaust gas driven turbocharger as claimed in claim 5, wherein said bearing outer ring defines a circumferentially extending passage circumscribing said outer ring, said second portion of said lubrication passage means communicating lubricating fluid into said circumferentially extending passage, and means for communicating said lubricating fluid from said circumferentially extending passage to said bearing elements. 
     
     
       8. Exhaust gas driven turbocharger as claimed in claim 7, wherein said means for communicating said lubricating fluid from said circumferentially extending passage to said bearing elements includes a feed passage extending through said bearing outer ring to communicate said circumferentially extending passage with said bearing elements. 
     
     
       9. Exhaust gas driven turbocharger as claimed in claim 8, wherein said feed passage includes a flow restricting orifice to squirt lubricating fluid on said bearing elements at a relatively high velocity. 
     
     
       10. Exhaust gas driven turbocharger as claimed in claim 3, wherein said bearing outer ring includes an inner circumferential surface engaging said bearing elements and an outer circumferential surface, a circumferentially extending groove in said outer surface of said bearing outer ring circumscribing said bearing outer ring, said lubrication passage means communicating lubricating fluid to said groove, and a feed passage for communicating said lubricating fluid through said bearing outer ring from said groove to said bearing elements. 
     
     
       11. Exhaust gas driven turbocharger as claimed in claim 10, wherein said feed passage includes a flow restricting orifice to squirt lubricating fluid on said bearing elements at a relatively high velocity. 
     
     
       12. Exhaust gas drive turbocharger as claimed in claim 10, wherein said outer circumferential surface of said bearing outer ring cooperates with said housing to define a circumferentially extending intersticial space about said bearing outer race receiving a film of lubricating fluid from said groove to dampen movement of said bearing means.